docs: def _stop_lock_renewer(self):
          """
          Stop the lock renewer.
  
          This signals the renewal thread and waits for its exit.
          """
          if self._lock_renewal_thread is None or not self._lock_renewal_thread.is_alive():
              return
          logger.debug("Signalling the lock refresher to stop")
          self._lock_renewal_stop.set()
          self._lock_renewal_thread.join()
          self._lock_renewal_thread = None
          logger.debug("Lock refresher has stopped")